air from anti shudder valve going back into turbo compressor, is it meant to do this?

[arron1995]

so after my recent post and noticing my turbo fluttering when i turn the car off, i decided to try some things out, i detached the hose from the intercooler to the charge pipe and the turbo no longer fluttered, so this got me realising, that when i turn the car off and the asv shuts, its sending air back through the charge pipe and into the turbo, surely this isnt healthy? when i turn the car off with everything attached, a puff of air comes into the intake from the turbo, if i remove the intercooler hose it goes away, is something wrong here?

[Stevey Y]

4 hours ago, arron1995 said:

so after my recent post and noticing my turbo fluttering when i turn the car off, i decided to try some things out, i detached the hose from the intercooler to the charge pipe and the turbo no longer fluttered, so this got me realising, that when i turn the car off and the asv shuts, its sending air back through the charge pipe and into the turbo, surely this isnt healthy? when i turn the car off with everything attached, a puff of air comes into the intake from the turbo, if i remove the intercooler hose it goes away, is something wrong here?

Hi wrong, the ASV closes to eliminate any further air going in when the engine stops once stopped the butterfly valve promptly goes back to its vertical position [wide open] until the ECU tells it to assume its starting position when the ignition key/button is at position two, as for the fluttering all turbos run on a couple of second after the engine shuts down, on the old turbines back in the eighties the advice was to sit there idling for at least five minuets after a run to allow the turbo to slow down, the bearing shafts on these old units ran in a small bath of oil but anything after that was pressure fed with oil so the bearing chamber is fed until the bearings stop moving, removing the pipe just dissipates the last of the air more quickly.

Steve.

[arron1995]

23 hours ago, Stevey Y said:

Hi wrong, the ASV closes to eliminate any further air going in when the engine stops once stopped the butterfly valve promptly goes back to its vertical position [wide open] until the ECU tells it to assume its starting position when the ignition key/button is at position two, as for the fluttering all turbos run on a couple of second after the engine shuts down, on the old turbines back in the eighties the advice was to sit there idling for at least five minuets after a run to allow the turbo to slow down, the bearing shafts on these old units ran in a small bath of oil but anything after that was pressure fed with oil so the bearing chamber is fed until the bearings stop moving, removing the pipe just dissipates the last of the air more quickly.

Steve.

what confuses me though steve is that i never got turbo flutter on my petrol turbo, i assume this is because it had a diverter? i know turbos take a while to spin down after shut off but why is it fluttering like its chopping the air? im sure its only started doing it recently, its 100% flutter as like i say i got a pop noise and the air shoots through the intake hose and out of the airbox. here is a video of the noise.

[Stevey Y]

Hi you won't get that on a petrol vehicle as its as you say a different set up, what you describe as turbo flutter sounds very much like the EGR doing its repositioning cycle my car does it and has done since the day I got it 62k ago, I think you are possibly over reacting to a noise that has probably been there all along I seriously don't think your vehicle has any major problem.

Steve.

[arron1995]

32 minutes ago, Stevey Y said:

Hi you won't get that on a petrol vehicle as its as you say a different set up, what you describe as turbo flutter sounds very much like the EGR doing its repositioning cycle my car does it and has done since the day I got it 62k ago, I think you are possibly over reacting to a noise that has probably been there all along I seriously don't think your vehicle has any major problem.

Steve.

egr valve is blanked mate, blanked at the exhaust manifold and the at the block, i had it blanked after it failed and its been mapped out along with dpf delete.

Edited October 18, 2021 by arron1995

[Stevey Y]

20 hours ago, arron1995 said:

egr valve is blanked mate, blanked at the exhaust manifold and the at the block, i had it blanked after it failed and its been mapped out along with dpf delete.

Hi it won't matter if the EGR is blanked and mapped out, if you removed the thing completely and blanked the feed you wold get an engine light up as although it no longer functions as it should it is almost a placebo effect as on a lot of the deletes that is part of the process of fooling the ECU into thinking its still there and working as it should, easy way to test the remap quality is unplug the valve and see if you get a light up, from experience a complete delete with the unit removed is very expensive and normally reserved for track cars, I watched one being done on a 330 BMW once and it took nearly three hours to do which involved removing the ECU and changing the chips inside.

Steve.

[arron1995]

1 hour ago, Stevey Y said:

Hi it won't matter if the EGR is blanked and mapped out, if you removed the thing completely and blanked the feed you wold get an engine light up as although it no longer functions as it should it is almost a placebo effect as on a lot of the deletes that is part of the process of fooling the ECU into thinking its still there and working as it should, easy way to test the remap quality is unplug the valve and see if you get a light up, from experience a complete delete with the unit removed is very expensive and normally reserved for track cars, I watched one being done on a 330 BMW once and it took nearly three hours to do which involved removing the ECU and changing the chips inside.

Steve.

the flutter coming from the turbo when i turn the car off, im 100% positive has only been happening since the car had the dpf gutted and egr blanked and mapped out, its 100% coming from the engine and back into the turbo, i removed the intercooler pipe from the left side, the one that attaches to the charge pipe that goes into the asv and when i turned the car off, after a couple seconds a big blast of air hit my hand, as long as it doesnt damage the turbo il leave it alone, but my track record of failed turbos isnt the best.

[Stevey Y]

1 hour ago, arron1995 said:

the flutter coming from the turbo when i turn the car off, im 100% positive has only been happening since the car had the dpf gutted and egr blanked and mapped out, its 100% coming from the engine and back into the turbo, i removed the intercooler pipe from the left side, the one that attaches to the charge pipe that goes into the asv and when i turned the car off, after a couple seconds a big blast of air hit my hand, as long as it doesnt damage the turbo il leave it alone, but my track record of failed turbos isnt the best.

Hi you didn't mention the DPF being filleted before, I would hazard a guess that your particular problem is a lack of back pressure allowing the compressor vanes to massively over run, I have seen this before down at Essex Turbos where they had built a Turbo for an RS Focus albeit petrol, the completely de restricted exhaust allied to the Mountune modifications, increased power band and horse power with added torque was causing massive overrun and the compressor vanes were breaking off, this explains the phenomenon you are experiencing as you no longer have the back pressure to slow the vanes down.

[arron1995]

27 minutes ago, Stevey Y said:

Hi you didn't mention the DPF being filleted before, I would hazard a guess that your particular problem is a lack of back pressure allowing the compressor vanes to massively over run, I have seen this before down at Essex Turbos where they had built a Turbo for an RS Focus albeit petrol, the completely de restricted exhaust allied to the Mountune modifications, increased power band and horse power with added torque was causing massive overrun and the compressor vanes were breaking off, this explains the phenomenon you are experiencing as you no longer have the back pressure to slow the vanes down.

do you think its likely to cause turbo failure? how would i go about fixing it.

[Stevey Y]

13 minutes ago, arron1995 said:

do you think its likely to cause turbo failure? how would i go about fixing it.

Hi personally I would leave it and see what occurs, otherwise you may well spend a fortune on retrofitting parts for no reason, maybe best if you ask whoever did the DPF core removal if what is happening to you is normal, I know for a fact that some of the drivers on my circuit had their DPF cores removed and experienced a droning inside the car afterwards allied to a louder exhaust note but as it turned out it was something they just had to live with and did not affect the life of the cars engine, as for Turbine failure the jury is still out on that one.

Steve.

[arron1995]

the guys who did it, il be honest are well known, but there replies are not the best, they tuned my car a week ago and still havent sent me my dyno printout, the reply i got when i sent them the video was "most turbo cars make the flutter" which i know isnt true.

[arron1995]

did some research steve and found this

"If the throttle valve is left operational w/ the EGR pipe blocked, there will be an intake vacuum as the valve cycles because the vacuum is not bled off by the exhaust entering the intake"

 

this probably explains the flutter, it will be vacuum.

[Stevey Y]

21 hours ago, arron1995 said:

did some research steve and found this

"If the throttle valve is left operational w/ the EGR pipe blocked, there will be an intake vacuum as the valve cycles because the vacuum is not bled off by the exhaust entering the intake"

 

this probably explains the flutter, it will be vacuum.

Hi the throttle valve is the anti shudder valve by another name, sounds like you have cracked it but I still have reservations as the  EGR will not be open when the car is started until the engine reaches operating temperature then when driving slowly through town it only pulses open just a smidgen to cut the emissions, when under hard acceleration it closes completely as the engine needs all the clean air it can get and it definitely shuts its valve when the engine is stopped, I can see the logic of having it deleted but the biggest villain of all the black tar is the PCV valve that allows water and engine vapour into the fresh air coming into the ASV, thats why most of the EGR deletes I have seen run a catch tank between the PCV and the charge pipe going to the compression side of the Turbo.

Steve,

[arron1995]

1 hour ago, Stevey Y said:

Hi the throttle valve is the anti shudder valve by another name, sounds like you have cracked it but I still have reservations as the  EGR will not be open when the car is started until the engine reaches operating temperature then when driving slowly through town it only pulses open just a smidgen to cut the emissions, when under hard acceleration it closes completely as the engine needs all the clean air it can get and it definitely shuts its valve when the engine is stopped, I can see the logic of having it deleted but the biggest villain of all the black tar is the PCV valve that allows water and engine vapour into the fresh air coming into the ASV, thats why most of the EGR deletes I have seen run a catch tank between the PCV and the charge pipe going to the compression side of the Turbo.

Steve,

the egr is blanked at turbo and block side mate and even if it did open which it shouldnt as its mapped out, it wont get into the intake manifold. i have noticed my boost at idle is a little higher than it was before the dpf delete etc, used to be 980hPa and now its 1020hPa which is technically just above vacuum. all i know is, since having all the work done, the flutter has appeared, my maf readings have changed as before the dpf/egr removal, my actual vs requested were the same, now my requested maf is 230 g/s and my actual is around 470 g/s at idle, im assuming because there is no exhaust gasses going back into the intake any longer that the maf will read higher due to more clean air.

 

i still need to figure out why my car makes a weird sort of rustling noise when i accelerate, it seems to be getting louder. its like when you swish a coin around in a jar. 

 

on another note i logged my boost yesterday and i think it needs toning down, its hitting 1.8 bar at times, im pretty sure the garret in these cannot handle that for very long.

Edited October 20, 2021 by arron1995